吉林西部沼泽湿地景观变化及其驱动机制分析

Analysis of wetland landscape pattern change and its driving mechanism in Jilin western part

以吉林西部农牧交错生态脆弱区作为研究案例，利用地形图和Landsat MSS、TM及ETM遥感数据，借助地理信息系统（GIS）的空间分析和地统计分析功能，研究沼泽湿地的景观格局变化及其驱动因素.结果表明，1954-2000年沼泽湿地面积呈先下降后上升的趋势，1954-1976年沼泽湿地面积急剧减少，到1996年以后，随着退耕还林还草政策的不断推进，沼泽湿地面积出现净增加；从景观梯度空间分布可见，该区的沼泽湿地主要分布于河漫滩、牛轭湖、古河道及阶地上的低洼地上，并且1954-2000年沼泽湿地景观梯度分布变化很大.从沼泽湿地景观格局的驱动因素看，气候暖、干化趋势成为沼泽湿地减少的重要原因之一，但是随着社会经济发展和人类活动强度的不断加大，人为因素对自然因素的放大作用是不可忽视的.

Using the farming-pastoral ecotonal weak zone in Jilin western part as the case example, and the terrain map and Landsat MSS, TM and ETM remote sensing data, to study the wetland landscape pattern change with the aid of GIS spatial analysis and geo-statistic analysis functions, to announce the driving factor of wetland landscape pattern change. The wetland area appeared the tendency of decreased firstly then increased in the year 1954 to 2000. From the year 1954 to 1976, the wetland area declined rapidly. After the year 1996, net increase appeared in the wetland area with the continuous carrying foreword of returning farmland to forest or grassland policy; From the spatial distribution of landscape gradient, it could be seen that the wetland of this area was located mainly in river floodplain, oxbow lake, paleochannel and low-lying land on bench. Moreover, the distinction change of wetland landscape gradient was obvious very great from the year 1954 to 2000. The climate warming and drying tendency had been one of the important causes for wetland reduction in that period. However, with social economic development and the continuous enlargement of human activity strength, the magnifying action of artificial factors to natural factors was not be ignored.